Multi frequency 2d phased array transducer

Abstract

Improved two-dimensional planar array transducer and beamformer apparatus and methods. In one embodiment, the two-dimensional planar array transducer is capable of simultaneously or sequentially forming multiple acoustic beams in two axes and at two or more widely separated acoustic frequencies from a single flat planar array transducer. The transducer planar array consists of two or more electrically and acoustically independent two dimensional planar transducer array structures operating at different frequencies that are physically integrated onto a single multi frequency configuration. In an exemplary embodiment, a second higher frequency transducer array is positioned within the aperture area of a lower frequency planar array transducer. Methods of using the aforementioned two-dimensional planar array transducer and beamformer are also disclosed.

Description

PRIORITY[0001]This application claims priority to U.S. Provisional Patent Application Ser. No. 61 / 456,086 filed Nov. 1, 2010 of the same title, which is incorporated herein by reference in its entirety.COPYRIGHT[0002]A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.1. FIELD OF THE INVENTION[0003]The present invention relates generally to a planar array sonar transducer and in one exemplary aspect to a multi-frequency planar array sonar transducer for generating acoustic Doppler current profiles.2. DESCRIPTION OF RELATED TECHNOLOGY[0004]Sonar transducers are currently used in different types of acoustic backscatter systems that measure velocity and / or distance in two or th...

AI Technical Summary

Benefits of technology

[0033]These and other aspects of the invention shall become apparent when considered in light of the disclosure provided herein.

Problems solved by technology

While these classes of 2D planar array sonars generally only require a single beamformer for transmit and / or receive thereby resulting in significantly less beamformer complexity, these types of alternate 2D planar array transducers have disadvantages such as having a fewer number of beams simultaneously formed and incomplete independence of the multiple 2D beams.

In addition, the range of frequencies which these 2D planar array transducers and beamformers can generate acoustic beams is limited by the bandwidth achievable by the bandwidth of the transducer array itself.

This two-transducer sonar provides the desired performance of high resolution over short range and long ranger lower resolution; however such a configuration is undesirable in that each transducer must be separately installed onto the vessel hull at locations where both transducer faces are exposed to the water.

Accordingly, when installed in a vessel hull, this two transducer approach requires two hull penetrations, which can: (1) be expensive to install; and (2) be difficult to locate in the hull.

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